ORIGINAL: Yoozername So you are using data with ranging errors to check dispersion? I don't follow that at all.

No. To check the final output. The dispersion is needed for the calculations but unless the formula produces real world results it's academic.

quote:

ORIGINAL: Yoozername Hopefully you can check my work and see if you agree. The thread is actually in regards to using zone-fire to bypass these ranging errors. Perhaps this side discussion would be better in a separate thread?

Give me some examples of guns with zones and I'll run the odds through my ballistics program.

WO 291/180 Do you have the conditions and methodology used in this report? What is the ranging error used? How many rounds were fired for each ranged test? What dispersion information is there? Basically you are saying that your program can achieve agreement with these two guns against TigerIe sized targets under the conditions tested? (stationary, hull up and down)

Give me some examples of guns with zones and I'll run the odds through my ballistics program.

Run the program for the conditions in the first post. That is, 75mmL48 firing APCR. T34/85 stationary face-on @300m. From 0-500 meters, what are the probabilities of being hit with 30% range estimation error in both directions (210m and 390m). If you could, explain how it's calculated in words if you do not want to reveal too much.

The block is using the unadjusted Bird-Livingston formula. The range number is the target distance. The aim is the point of aim with error. The P(Hit)% is the percent chance of hitting. Firing height=7ft.

Right now it only computes if the aim is greater or equal to the range. In a short aim when the projectile hits the ground the run is over. To work with the formula it would have to be made to continue on and pass beneath the target to find the distance from the path to the center of the target.

I can find precious few live fire accuracy tests. All I do find are British. Though the two don’t agree with each other. This table has an unknown target size. Assuming it is Panzer IV sized I ran another test with different gun heights and 25% ranging error. 17-pdr and 75mm match to a high degree. The 6-pdr doesn’t match the WO 291/180. And the APDS values seem highly optimistic.

How about entering 425 aim up to 411 range, enter 650 aim up till 640 range and 875 up to 869 range? That should work even though it isn't exactly the zone fire I would want. It could demonstrate some principles.

At 800 meters, you have about 1 out of 5 APCR shots missing the target T34 (I assume this is first round accuracy on a known range). The vertical 50% dispersion is 0.5 meters at 800 meters. Even if I use 3 sigma conversion, it is just barely over the target height. About 2.28m. The 0.14 meter distance, both over and under the target, represents, what...a 4-5%?